This is a short list of some of my favorite concept artists who make dieselpunk art. There are others I enjoy, but these popped out as my immediate favorites (and ones I post fairly often).
Keith Thompson
https://www.keiththompsonart.com/
Keith Thompson’s mix of dieselpunk, mecha and lovecraftian horrors puts him as my favorite concept artist period. His best dieselpunk work is for the book series Leviathan and the ‘Iron Grip’ games.
Makoto Kobayashi
http://aswars.tripod.com/
I don’t know if he has an official page or site anywhere so this is the best I can do. Makoto Kobayashi is a legend I wish more people knew of, seeing as he’s made so many iconic designs for anime and games. In terms of dieselpunk, he’s best known for his work on ‘Last Exile.’
Aoiwaffle0608
https://www.deviantart.com/aoiwaffle0608
Aoiwaffle0608 isn’t a professional artist and his art skill sometimes can’t fully pull off what he tries to do. However, his amazing designs and sheer depth of world design (going from the airships to uniforms to even the mess kits the soldiers use) earns him a spot on my list.
Michal Kus
https://www.artstation.com/michalkus
If you’re looking for big, solid, chunky airships, tanks and mechs with an absurd amount of details then Michal Kus is the one to go to. His best dieselpunk work is for the ‘Iron Grip’ games and most recently his WW2 series ‘Project: 1952.’
Walter Pezzali
http://futuristicrobots.blog.fc2.com/
Walter Pezzali is a weird inclusion on this list since although he does concept art…with him its all about his amazing retro-styled robot kit models.